Why did Byron and Shelley turn against Wordsworth?
It's a very interesting and not really examined angle that you raise here. There was a division between Wordsworth/ Coleridge and Byron/ Shelley, and to a lesser extent, Keats. Part of the reason for this schism was generational. The "younger" generation of Romantic poets (Byron and Shelley) felt that Wordsworth and Coleridge "sold out" their passions as they became older. Byron and Shelley were also more driven by a political and social aspect, in terms of embracing revolutionary change. Byron went so far as leading a small army as well as a seat in the House of Lords. Both Byron and Shelley felt that the older generation of Romantic poets were not as forceful in their demands for change, as well as feeling that the older generation was "more delicate" and less on the passionate side. Romantic poets truly believed that youth was the key to optimism, passion, and enthusiasm. This actually started with Wordsworth and Coleridge, but as they got older, Shelley and Byron embraced this idea and used it as a method of criticizing the "older generation" of Coleridge and Wordsworth.